1. Field of the Invention
The present invention relates to method and device for peeling a film laminated on a printed circuit board or the like.
2. Description of the Related Art
A printed circuit board for use in electronic equipment includes an insulation panel and wiring. The wiring is made of a material such as copper and has a given pattern formed on either one surface or both surfaces of the insulation panel. This type of printed circuit board is manufactured by the following process.
A laminated member consisting of a photosensitive resin (photoresist) layer and a light transmissive resin film (a protective film) is laminated by thermal pressure on a conductive layer provided on an insulation panel by use of a roller. Next, a wiring pattern film is further put on the laminated member, and the photoresist layer is exposed to light for a given period of time through the wiring pattern film and light transmissive resin film. After the light transmissive resin film is peeled off, the exposed photoresist layer is developed to thereby form an etching mask pattern. Then the unnecessary portions of the conductive layer are removed by etching, so that a printed circuit board having a given wiring pattern is formed.
Conventionally, there have been methods and devices for automatically peeling the above-mentioned protective film in the manufacturing process of the printed circuit board. For example, in Japanese Patent Publication No. 6-3550 of Heisei, a thin film peeling device includes a floating means which beats the end portion of a laminated thin film (consisting of a photoresist layer and a light transmissive resin film respectively put on a circuit board) with the vibration of a rod of a vibrator, to thereby float part of the light transmissive film from the photoresist layer.
When two laminated thin films are respectively put on both of the front and back surfaces of the circuit board, two vibrator rods are respectively provided on the front and back sides of the circuit board in such a manner that they are mutually opposed to each other. Thus, by beating synchronously the front and back sides of the circuit board with the leading ends of the rods through the laminated thin films, the circuit board is allowed to receive the same force from the front and back sides. The result is to prevent distortion of the circuit board.
However, when the two laminated thin films are coated on the front and back sides of the circuit board as mentioned above, the coated positions can vary relative to each other. In this case, the positions of the end portions of the laminated thin films in the advancing direction of the circuit board raise a problem in connection with the peeling positions thereof. To absorb such great variations, it can be expected that, while moving the leading ends of the rods in a relatively great stroke from the positions of the end portions of the mutually displaced films, the end portions of the laminated thin film are beaten assuredly by the rods leading ends to thereby float the same.
In this case, the positions of the ends of the laminated thin films are detected by a sensor to thereby determine the starting points of vibration application by the rods of the vibrators. However, if the starting points are very close to the leading end of the circuit board in the advancing direction thereof, then the leading ends of the vibrator rods may perform a circuit board beating operation off of the circuit board. This causes the two rods leading ends to beat each other idly and thereby damage themselves.
Also, when a pair of vibrator rods are disposed on the front and back sides of a thin circuit board in a mutually opposing manner as in the above-mentioned conventional peeling device, then the circuit board is caused to deform. Therefore, the positions of the upper and lower rods must be set with considerably high precision.